1. Technical Field
This invention relates generally to rechargeable battery packs, and more specifically to spacer devices for mounting circuit boards and cells within a rechargeable battery pack.
2. Background Art
Portable devices rely upon rechargeable batteries for their portability. The batteries used in these devices are more than merely rechargeable cells. Most battery packs are packaged devices with plastic housings that include many different components. They often include circuit boards with charging circuitry and protection circuitry, and sometimes fuel gauging circuitry. Further, they generally include electrical conduit to make connections from the cell and circuitry to the external terminals on the outer housing.
The conventional way to connect all of these interior components was with a hand-soldered wire. Wire is soldered from the can of the rechargeable cell to the circuitry, then to the external terminals. The problem with this method is quality. For example, cold solder joints, prevalent in any hand-soldering operation, can cause the electrical connections inside the battery pack to open. Cold solder joints thus render the battery pack useless. Additionally, solder balls can cause shorts within the battery pack, again compromising reliability.
Another method of xe2x80x9chooking upxe2x80x9d all the internal components of a battery pack is with a flexible circuit. Such a solution employs Kapton(copyright) encapsulated metal with circuit components coupled thereto. Such a solution is taught in U.S. Pat. No. 6,153,834, entitled xe2x80x9cFlexible circuit with tabs for connection to battery cellsxe2x80x9d, issued Nov. 28, 2000, assigned to Motorola, Inc.
While this solution is effective, Kapton(copyright) is quite expensive. With the cost of many electronic devices, like cellular phones, falling well below $100, manufacturers have less money to devote to the battery pack. There is thus a need for an improved, low cost, connection means for rechargeable battery packs.